Nextcloud snap - disable LetsEncrypt?


I have been using Nextcloud Snap for some time now, and have been very happy with it.
Today my public IP is natted directly into the VM on TCP/80 & TCP/443 - but i would like to use that IP for more web services - so i installed an Nginx Proxy Manager.

The Nginx will take over the SSL termination / LetsEncrypt part.
But i should probably disable the LetsEncrypt service on my Nextcloud snap installation - my question is how do i do that?

I need an answer to this, as well, please.